如何在C# WPF中选中/取消选中列表框中的所有复选框？

private void SelectAllCheckBoxes()
{
    foreach (var item in myListBox.Items)
    {
        ListBoxItem listBoxItem = (ListBoxItem)myListBox.ItemContainerGenerator.ContainerFromItem(item);
        CheckBox checkBox = FindVisualChild<CheckBox>(listBoxItem);
        if (checkBox != null)
        {
            checkBox.IsChecked = true;
        }
    }
}

private void DeselectAllCheckBoxes()
{
    foreach (var item in myListBox.Items)
    {
        ListBoxItem listBoxItem = (ListBoxItem)myListBox.ItemContainerGenerator.ContainerFromItem(item);
        CheckBox checkBox = FindVisualChild<CheckBox>(listBoxItem);
        if (checkBox != null)
        {
            checkBox.IsChecked = false;
        }
    }
}

private T FindVisualChild<T>(DependencyObject parent) where T : DependencyObject
{
    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
    {
        DependencyObject child = VisualTreeHelper.GetChild(parent, i);
        if (child != null && child is T)
        {
            return (T)child;
        }
        else
        {
            T childOfChild = FindVisualChild<T>(child);
            if (childOfChild != null)
            {
                return childOfChild;
            }
        }
    }
    return null;
}